from archives.
Copyright @copyright{} 1992, 1994, 1995, 1996, 1997, 1999, 2000, 2001,
-2003, 2004, 2005, 2006 Free Software Foundation, Inc.
+2003, 2004, 2005, 2006, 2007 Free Software Foundation, Inc.
@quotation
Permission is granted to copy, distribute and/or modify this document
@opsummary{exclude-caches}
@item --exclude-caches
-Automatically excludes all directories
-containing a cache directory tag. @xref{exclude}.
+Exclude from dump any directory containing a valid cache directory
+tag file, but still dump the directory node and the tag file itself.
+
+@xref{exclude}.
+
+@opsummary{exclude-caches-under}
+@item --exclude-caches-under
+
+Exclude from dump any directory containing a valid cache directory
+tag file, but still dump the directory node itself.
+
+@xref{exclude}.
+
+@opsummary{exclude-caches-all}
+@item --exclude-caches-all
+
+Exclude from dump any directory containing a valid cache directory
+tag file. @xref{exclude}.
@opsummary{exclude-tag}
@item --exclude-tag=@var{file}
-Exclude all directories, containing file named @var{file}. @xref{exclude}.
+Exclude from dump any directory containing file named @var{file}, but
+dump the directory node and @var{file} itself. @xref{exclude}.
+
+@opsummary{exclude-tag-under}
+@item --exclude-tag-under=@var{file}
+
+Exclude from dump the contents of any directory containing file
+named @var{file}, but dump the directory node itself. @xref{exclude}.
+
+@opsummary{exclude-tag-all}
+@item --exclude-tag-all=@var{file}
+
+Exclude from dump any directory containing file named @var{file}.
+@xref{exclude}.
@opsummary{file}
@item --file=@var{archive}
single line @file{*.o}, no files whose names end in @file{.o} will be
added to the archive.
-@table @option
-@opindex exclude-caches
-@item --exclude-caches
-Causes @command{tar} to ignore directories containing a cache directory tag.
-@end table
-
@findex exclude-caches
-When creating an archive, the @option{--exclude-caches} option causes
-@command{tar} to exclude all directories that contain a @dfn{cache
+When creating an archive, the @option{--exclude-caches} option family
+causes @command{tar} to exclude all directories that contain a @dfn{cache
directory tag}. A cache directory tag is a short file with the
well-known name @file{CACHEDIR.TAG} and having a standard header
specified in @url{http://www.brynosaurus.com/cachedir/spec.html}.
use to hold regenerable, non-precious data, so that such data can be
more easily excluded from backups.
+There are three @samp{exclude-caches} option, providing a different
+exclusion semantics:
+
+@table @option
+@opindex exclude-caches
+@item --exclude-caches
+Do not archive the contents of the directory, but archive the
+directory itself and the @file{CACHEDIR.TAG} file.
+
+@opindex exclude-caches-under
+@item --exclude-caches-under
+Do not archive the contents of the directory, nor the
+@file{CACHEDIR.TAG} file, archive only the directory itself.
+
+@opindex exclude-caches-all
+@item --exclude-caches-all
+Omit directories containing @file{CACHEDIR.TAG} file entirely.
+@end table
+
@findex exclude-tag
-Another option, @option{--exclude-tag}, provides a generalization of
+Another option family, @option{--exclude-tag}, provides a generalization of
this concept. It takes a single argument, a file name to look for.
Any directory that contains this file will be excluded from the dump.
+Similarly to @samp{exclude-caches}, there are three options in this
+option family:
@table @option
@opindex exclude-tag
@item --exclude-tag=@var{file}
-Causes @command{tar} to ignore directories containing @var{file}.
-Multiple @option{--exclude-tag} options can be given.
+Do not dump the contents of the directory, but dump the
+directory itself and the @var{file}.
+
+@opindex exclude-tag-under
+@item --exclude-tag-under=@var{file}
+Do not dump the contents of the directory, nor the
+@var{file}, archive only the directory itself.
+
+@opindex exclude-tag-all
+@item --exclude-tag-all=@var{file}
+Omit directories containing @var{file} file entirely.
@end table
-For example:
+Multiple @option{--exclude-tag*} options can be given.
+
+For example, given this directory:
@smallexample
+@group
$ @kbd{find dir}
dir
dir/blues
dir/jazz
dir/folk
dir/folk/tagfile
-$ @kbd{tar -cf archive.tar --exclude-tag=tagfile -v}
+dir/folk/sanjuan
+dir/folk/trote
+@end group
+@end smallexample
+
+The @option{--exclude-tag} will produce the following:
+
+@smallexample
+$ @kbd{tar -cf archive.tar --exclude-tag=tagfile -v dir}
dir/
dir/blues
dir/jazz
-./tar: dir/folk/: contains a cache directory tag tagfile; not dumped
-$ @kbd{tar -tf archive.tar}
+dir/folk/
+tar: dir/folk/: contains a cache directory tag tagfile;
+ contents not dumped
+dir/folk/tagfile
+@end smallexample
+
+Both the @file{dir/folk} directory and its tagfile are preserved in
+the archive, however the rest of files in this directory are not.
+
+Now, using the @option{--exclude-tag-under} option will exclude
+@file{tagfile} from the dump, while still preserving the directory
+itself, as shown in this example:
+
+@smallexample
+$ @kbd{tar -cf archive.tar --exclude-tag-under=tagfile -v dir}
dir/
dir/blues
dir/jazz
+dir/folk/
+./tar: dir/folk/: contains a cache directory tag tagfile;
+ contents not dumped
+@end smallexample
+
+Finally, using @option{--exclude-tag-all} omits the @file{dir/folk}
+directory entirely:
+
+@smallexample
+$ @kbd{tar -cf archive.tar --exclude-tag-all=tagfile -v dir}
+dir/
+dir/blues
+dir/jazz
+./tar: dir/folk/: contains a cache directory tag tagfile;
+ directory not dumped
@end smallexample
@menu
Any @command{tar} implementation will be able to extract sparse members from a
PAX archive. However, the extracted files will be @dfn{condensed},
i.e., any zero blocks will be removed from them. When we restore such
-a condensed file to its original form, by adding zero bloks (or
+a condensed file to its original form, by adding zero blocks (or
@dfn{holes}) back to their original locations, we call this process
@dfn{expanding} a compressed sparse file.
@file{@var{name}}.
@end enumerate
-In the unlikely case when this algorithm does not suite your needs,
+In the unlikely case when this algorithm does not suit your needs,
you can explicitly specify output file name as a second argument to
the command:
that precedes an archive member and contains a set of
@dfn{variables}, describing the member properties that cannot be
stored in the standard @code{ustar} header. While optional for
-expanding sparse version 1.0 members, use of extended headers is
+expanding sparse version 1.0 members, the use of extended headers is
mandatory when expanding sparse members in older sparse formats: v.0.0
and v.0.1 (The sparse formats are described in detail in @ref{Sparse
-Formats}.) So, for this format, the question is: how to obtain
+Formats}.) So, for these formats, the question is: how to obtain
extended headers from the archive?
If you use a @command{tar} implementation that does not support PAX
@item TAR_FORMAT
Format of the archive being processed. @xref{Formats}, for a complete
list of archive format names.
+
+@vrindex TAR_FD, info script environment variable
+@item TAR_FD
+File descriptor which can be used to communicate the new volume
+name to @command{tar}.
@end table
The volume script can instruct @command{tar} to use new archive name,
-by writing in to file descriptor 3 (see below for an example).
+by writing in to file descriptor @env{$TAR_FD} (see below for an example).
If the info script fails, @command{tar} exits; otherwise, it begins
writing the next volume.
prompt.
Finally, the most flexible approach is to use a volume script, that
-writes new archive name to the file descriptor #3. For example, the
+writes new archive name to the file descriptor @env{$TAR_FD}. For example, the
following volume script will create a series of archive files, named
@file{@var{archive}-@var{vol}}, where @var{archive} is the name of the
archive being created (as given by @option{--file} option) and
*) exit 1
esac
-echo $@{name:-$TAR_ARCHIVE@}-$TAR_VOLUME >&3
+echo $@{name:-$TAR_ARCHIVE@}-$TAR_VOLUME >&$TAR_FD
@end group
@end smallexample
projects / chaz / tar / blobdiff